demux_lavf: report program_id

This can be useful in stream selection.

demux/demux.c

@@ -978,6 +978,7 @@ struct sh_stream *demux_alloc_sh_stream(enum stream_type type)
         .index = -1,
         .ff_index = -1,     // may be overwritten by demuxer
         .demuxer_id = -1,   // ... same
+        .program_id = -1,   // ... same
         .codec = talloc_zero(sh, struct mp_codec_params),
         .tags = talloc_zero(sh, struct mp_tags),
     };

demux/demux_lavf.c

@@ -832,6 +832,9 @@ static void handle_new_stream(demuxer_t *demuxer, int i)
         if (lang && lang->value && strcmp(lang->value, "und") != 0)
             sh->lang = talloc_strdup(sh, lang->value);
         sh->hls_bitrate = dict_get_decimal(st->metadata, "variant_bitrate", 0);
+        AVProgram *prog = av_find_program_from_stream(avfc, NULL, i);
+        if (prog)
+            sh->program_id = prog->id;
         sh->missing_timestamps = !!(priv->avif_flags & AVFMT_NOTIMESTAMPS);
         mp_tags_copy_from_av_dictionary(sh->tags, st->metadata);
         demux_add_sh_stream(demuxer, sh);

demux/stheader.h

@@ -51,6 +51,7 @@ struct sh_stream {
     bool image;                 // video stream is an image
     bool still_image;           // video stream contains still images
     int hls_bitrate;
+    int program_id;
 
     struct mp_tags *tags;